The Three Fundamental Principles and the Four Basic Rules of Islam.
Author: Muhammad Bin Abdul Wahhab
Publisher: Daar Al-Watan
Source: http://www.islamhouse.com/p/1333
Islam, is a comprehensive way of Life, does not confine itself to the spiritual aspect of man's life only, rather its primary concern is with the application of its rules to the daily life of man, the author wrote it in an easy and simple method to achieve the very purpose of the book, namely introducing Islam to Muslims and non-Muslims, through the best and simplest way.
Author: Hammodah Abd al-Aati
Publisher: http://www.islamweb.net - Islam Web Website
A monumental work discussing the Makkan period of the Prophet's life, and a refutation of Orientalist attacks.
Author: Muhammad Mohar Ali - Mohammed Mahr Ali
A nice discussion of some important points needed by those callling to Islam
Source: http://www.islamhouse.com/p/1243
A wonderful booklet mentions the predictions about the Prophet Muhammed (Peace be upon him) in Psalm, Old Testament and New Testament. It also discusses some other issues.
Publisher: http://www.rasoulallah.net - Website of Rasoulullah (peace be upon him)
An excellent 18 page treatise upon the excellence of Hajj and its rulings. Taken from Silsilah Ahadeeth As-Saheehah & Silsilah Ahadeeth Ad-Daeefah. Translated by Abbas Abu Yahya
Author: Muhammad Naasiruddeen al-Albaanee
Translators: Abbas Abu Yahya